diff --git a/application/Espo/Core/Currency/CalculatorUtil.php b/application/Espo/Core/Currency/CalculatorUtil.php
new file mode 100644
index 0000000000..e925c18646
--- /dev/null
+++ b/application/Espo/Core/Currency/CalculatorUtil.php
@@ -0,0 +1,122 @@
+<?php
+/************************************************************************
+ * This file is part of EspoCRM.
+ *
+ * EspoCRM - Open Source CRM application.
+ * Copyright (C) 2014-2022 Yurii Kuznietsov, Taras Machyshyn, Oleksii Avramenko
+ * Website: https://www.espocrm.com
+ *
+ * EspoCRM is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * EspoCRM is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with EspoCRM. If not, see http://www.gnu.org/licenses/.
+ *
+ * The interactive user interfaces in modified source and object code versions
+ * of this program must display Appropriate Legal Notices, as required under
+ * Section 5 of the GNU General Public License version 3.
+ *
+ * In accordance with Section 7(b) of the GNU General Public License version 3,
+ * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
+ ************************************************************************/
+
+namespace Espo\Core\Currency;
+
+use DivisionByZeroError;
+
+class CalculatorUtil
+{
+    private const SCALE = 14;
+
+    public static function add(string $arg1, string $arg2): string
+    {
+        if (!function_exists('bcadd')) {
+            return (string) (
+                (float) $arg1 + (float) $arg2
+            );
+        }
+
+        return bcadd(
+            $arg1,
+            $arg2,
+            self::SCALE
+        );
+    }
+
+    public static function subtract(string $arg1, string $arg2): string
+    {
+        if (!function_exists('bcsub')) {
+            return (string) (
+                (float) $arg1 - (float) $arg2
+            );
+        }
+
+        return bcsub(
+            $arg1,
+            $arg2,
+            self::SCALE
+        );
+    }
+
+    public static function multiply(string $arg1, string $arg2): string
+    {
+        if (!function_exists('bcmul')) {
+            return (string) (
+                (float) $arg1 * (float) $arg2
+            );
+        }
+
+        return bcmul(
+            $arg1,
+            $arg2,
+            self::SCALE
+        );
+    }
+
+    public static function divide(string $arg1, string $arg2): string
+    {
+        if (!function_exists('bcdiv')) {
+            return (string) (
+                (float) $arg1 / (float) $arg2
+            );
+        }
+
+        $result = bcdiv(
+            $arg1,
+            $arg2,
+            self::SCALE
+        );
+
+        if ($result === null) {
+            throw new DivisionByZeroError();
+        }
+
+        return $result;
+    }
+
+    public static function round(string $arg, int $precision = 0): string
+    {
+        if (!function_exists('bcadd')) {
+            return (string) round((float) $arg, $precision);
+        }
+
+        $addition = '0.' . str_repeat('0', $precision) . '5';
+
+        if ($arg[0] === '-') {
+            $addition = '-' . $addition;
+        }
+
+        return bcadd(
+            $arg,
+            $addition,
+            $precision
+        );
+    }
+}
diff --git a/application/Espo/Core/Currency/Converter.php b/application/Espo/Core/Currency/Converter.php
index 30078a179d..e568fc2e9d 100644
--- a/application/Espo/Core/Currency/Converter.php
+++ b/application/Espo/Core/Currency/Converter.php
@@ -52,21 +52,42 @@ class Converter
      */
     public function convert(Currency $value, string $targetCurrencyCode): Currency
     {
-        $amount = $value->getAmount();
-
         if (!$this->configDataProvider->hasCurrency($targetCurrencyCode)) {
             throw new RuntimeException("Can't convert currency to unknown currency '{$targetCurrencyCode}.");
         }
 
         $rate = $this->configDataProvider->getCurrencyRate($value->getCode());
-
         $targetRate = $this->configDataProvider->getCurrencyRate($targetCurrencyCode);
 
-        $amount *= $rate;
+        $convertedAmount = $this->convertAmount($value->getAmountAsString(), $rate, $targetRate);
 
-        $amount /= $targetRate;
+        return new Currency($convertedAmount, $targetCurrencyCode);
+    }
 
-        return new Currency($amount, $targetCurrencyCode);
+    /**
+     * Convert a currency value to a specific currency with specific rates.
+     * Base currency should has rate equal to `1.0`.
+     *
+     * @throws RuntimeException
+     */
+    public function convertWithRates(Currency $value, string $targetCurrencyCode, Rates $rates): Currency
+    {
+        $currencyCode = $value->getCode();
+
+        if (!$rates->hasRate($currencyCode)) {
+            throw new RuntimeException("No rate for the currency '{$currencyCode}.");
+        }
+
+        if (!$rates->hasRate($targetCurrencyCode)) {
+            throw new RuntimeException("No rate for the currency '{$targetCurrencyCode}.");
+        }
+
+        $rate = $rates->getRate($currencyCode);
+        $targetRate = $rates->getRate($targetCurrencyCode);
+
+        $convertedAmount = $this->convertAmount($value->getAmountAsString(), $rate, $targetRate);
+
+        return new Currency($convertedAmount, $targetCurrencyCode);
     }
 
     /**
@@ -79,34 +100,11 @@ class Converter
         return $this->convert($value, $targetCurrencyCode);
     }
 
-    /**
-     * Convert a currency value to a specific currency with specific rates.
-     * Base currency should has rate equal to `1.0`.
-     *
-     * @throws RuntimeException
-     */
-    public function convertWithRates(Currency $value, string $targetCurrencyCode, Rates $rates): Currency
+    private function convertAmount(string $amount, float $rate, float $targetRate): string
     {
-        $amount = $value->getAmount();
-
-        $currencyCode = $value->getCode();
-
-        if (!$rates->hasRate($currencyCode)) {
-            throw new RuntimeException("No rate for the currency '{$currencyCode}.");
-        }
-
-        if (!$rates->hasRate($targetCurrencyCode)) {
-            throw new RuntimeException("No rate for the currency '{$targetCurrencyCode}.");
-        }
-
-        $rate = $rates->getRate($currencyCode);
-
-        $targetRate = $rates->getRate($targetCurrencyCode);
-
-        $amount *= $rate;
-
-        $amount /= $targetRate;
-
-        return new Currency($amount, $targetCurrencyCode);
+        return CalculatorUtil::divide(
+            CalculatorUtil::multiply($amount, (string) $rate),
+            (string) $targetRate
+        );
     }
 }
diff --git a/application/Espo/Core/Field/Currency.php b/application/Espo/Core/Field/Currency.php
index e61f106d8a..3f8412fa2e 100644
--- a/application/Espo/Core/Field/Currency.php
+++ b/application/Espo/Core/Field/Currency.php
@@ -29,33 +29,56 @@
 
 namespace Espo\Core\Field;
 
+use Espo\Core\Currency\CalculatorUtil;
+
 use RuntimeException;
+use InvalidArgumentException;
 
 /**
  * A currency value object. Immutable.
  */
 class Currency
 {
-    private $amount;
+    private string $amount;
 
-    private $code;
+    private string $code;
 
-    public function __construct(float $amount, string $code)
+    /**
+     * @param string|float $amount
+     * @throws RuntimeException
+     */
+    public function __construct($amount, string $code)
     {
+        if (!is_string($amount) && !is_float($amount)) {
+            throw new InvalidArgumentException();
+        }
+
         if (strlen($code) !== 3) {
             throw new RuntimeException("Bad currency code.");
         }
 
+        if (is_float($amount)) {
+            $amount = (string) $amount;
+        }
+
         $this->amount = $amount;
         $this->code = $code;
     }
 
+    /**
+     * Get an amount as string.
+     */
+    public function getAmountAsString(): string
+    {
+        return $this->amount;
+    }
+
     /**
      * Get an amount.
      */
     public function getAmount(): float
     {
-        return $this->amount;
+        return (float) $this->amount;
     }
 
     /**
@@ -71,13 +94,14 @@ class Currency
      */
     public function add(self $value): self
     {
-        $amount = $this->getAmount();
-
         if ($this->getCode() !== $value->getCode()) {
             throw new RuntimeException("Can't add a currency value with a different code.");
         }
 
-        $amount += $value->getAmount();
+        $amount = CalculatorUtil::add(
+            $this->getAmountAsString(),
+            $value->getAmountAsString()
+        );
 
         return new self($amount, $this->getCode());
     }
@@ -87,13 +111,14 @@ class Currency
      */
     public function subtract(self $value): self
     {
-        $amount = $this->getAmount();
-
         if ($this->getCode() !== $value->getCode()) {
             throw new RuntimeException("Can't substract a currency value with a different code.");
         }
 
-        $amount -= $value->getAmount();
+        $amount = CalculatorUtil::subtract(
+            $this->getAmountAsString(),
+            $value->getAmountAsString()
+        );
 
         return new self($amount, $this->getCode());
     }
@@ -103,9 +128,10 @@ class Currency
      */
     public function multiply(float $multiplier): self
     {
-        $amount = $this->getAmount();
-
-        $amount *= $multiplier;
+        $amount = CalculatorUtil::multiply(
+            $this->getAmountAsString(),
+            (string) $multiplier
+        );
 
         return new self($amount, $this->getCode());
     }
@@ -115,9 +141,10 @@ class Currency
      */
     public function divide(float $divider): self
     {
-        $amount = $this->getAmount();
-
-        $amount /= $divider;
+        $amount = CalculatorUtil::divide(
+            $this->getAmountAsString(),
+            (string) $divider
+        );
 
         return new self($amount, $this->getCode());
     }
@@ -127,15 +154,18 @@ class Currency
      */
     public function round(int $precision = 0): self
     {
-        $amount = round($this->getAmount(), $precision);
+        $amount = CalculatorUtil::round($this->getAmountAsString(), $precision);
 
         return new self($amount, $this->getCode());
     }
 
     /**
      * Create from an amount and code.
+     *
+     * @param string|float $amount
+     * @throws RuntimeException
      */
-    public static function create(float $amount, string $code): self
+    public static function create($amount, string $code): self
     {
         return new self($amount, $code);
     }
diff --git a/tests/unit/Espo/Core/Field/Currency/CurrencyConverterTest.php b/tests/unit/Espo/Core/Field/Currency/CurrencyConverterTest.php
index 71371883f4..df0af36d09 100644
--- a/tests/unit/Espo/Core/Field/Currency/CurrencyConverterTest.php
+++ b/tests/unit/Espo/Core/Field/Currency/CurrencyConverterTest.php
@@ -38,11 +38,6 @@ use Espo\Core\{
 
 class CurrencyConverterTest extends \PHPUnit\Framework\TestCase
 {
-    protected function setUp() : void
-    {
-
-    }
-
     public function testConvert1()
     {
         $currencyConfigDataProvider = $this->createMock(CurrencyConfigDataProvider::class);
diff --git a/tests/unit/Espo/Core/Field/Currency/CurrencyTest.php b/tests/unit/Espo/Core/Field/Currency/CurrencyTest.php
index 6d3623bb0b..8963663c09 100644
--- a/tests/unit/Espo/Core/Field/Currency/CurrencyTest.php
+++ b/tests/unit/Espo/Core/Field/Currency/CurrencyTest.php
@@ -95,15 +95,42 @@ class CurrencyTest extends \PHPUnit\Framework\TestCase
         $this->assertEquals('USD', $value->getCode());
     }
 
-    public function testRound()
+    public function testRound1()
     {
         $value = (new Currency(2.306, 'USD'))->round(2);
 
         $this->assertEquals(2.31, $value->getAmount());
-
         $this->assertEquals('USD', $value->getCode());
     }
 
+    public function testRound2()
+    {
+        $value = (new Currency(2.306, 'USD'))->round(4);
+
+        $this->assertEquals(2.306, $value->getAmount());
+    }
+
+    public function testRound3()
+    {
+        $value = (new Currency(2.306, 'USD'))->round(0);
+
+        $this->assertEquals(2, $value->getAmount());
+    }
+
+    public function testRound4()
+    {
+        $value = (new Currency(-2.306, 'USD'))->round(2);
+
+        $this->assertEquals(-2.31, $value->getAmount());
+    }
+
+    public function testRound5()
+    {
+        $value = (new Currency(-2.5, 'USD'))->round(0);
+
+        $this->assertEquals(-3, $value->getAmount());
+    }
+
     public function testBadAdd()
     {
         $this->expectException(RuntimeException::class);